I'm just trying to picture the water passages..... if water is going uphill then goes downhill and there's a pocket of water that cannot be purged out, I'd think that it would freeze in there.... and if it was in a location that was tight, the only way for the ice to expand it for something to break.
take for instance the 1/2 inch block plug..... is it at the very bottom of the water passage, or is it an inch above the passage? If it's above, then you've got an inch that'll freeze. then you've got the nose up tilt of the engine block..... what about the water from the plug to the back of the block?
Maybe I'm overthinking it.... but if this were the case, seems like PCM, Indmar, and others would lust have the valves in place to begin with.
and what about the water at the thermostat housing?
best pic I could find..... but I'd say water will sit in the places indicated....
Last edited by milkmania; 12-12-2012 at 04:27 PM.